Transmission mechanism



Nov. 18, 1952 R. P. CLIFTON TRANSMISSION MECHANISM Filed Dec. 1, 1945 IN VEN TOR.

Patented Nov. 18, 1952 TRANSMISSKON MECHANISM Robert P. Clifton, Dearborn, Mich, assignor to Packard Motor Carj Company, Detroit, Mich, a corporation of Michigan Application Decenriloer 1, 1945, Serial No. 632,266

(Cl. Yd-e732) 10 Claims. 1

This invention relates to transmission mechanism of the type embodying a power driven fluid coupling and multiple ratio planetary gearing,

One of the objects of the invention is to provide a transmission of the type referred to in which the-component parts are associated to form a compact structure.

Another object of the invention is to provide planetary gearing through which three gear ratio drives may be selectively established by a pair of control devices coacting with the planet gear carrier.

Still another object of the invention is to arrange reverse drive mechanism between planetary and a tail shaft so that it will occupy previously unused space and thereby reduce the overall length of the structure. I

A further object of the invention is to obtain maximum torque in the low speed drive of a multi speed transmission, in which a fluid coupling drives planetary gearing, by mechanically connecting the drive shaft with the gearing.

Another object of the invention is to provide a fluid coupling driven planetary gearing in which high speed drive is obtained by a two path power flow between the fluid coupling and the gearing, one path being a mechanical connection in low speed drive and the other path being the mechanical connection and the fluid coupling in high speed drive.

Other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a longitudinal sectional view of a transmission mechanism incorporating the invention;

Fig. 2 is a sectional view of the torque-speed device forming. a driving connection and hydraulic control taken on line 2-..2- of Fig. 1;

Fig; 3 is a diagrammatic View of control mechanism for the transmission mechanism;

Fig. 4 isa diagrammatic view of a linkage system for manually setting the control valves.

Referring to the drawings by characters of reference, the power transmission mechanism comprises generally apower unit, such as an engine of which the rear wall it and crankshaft H are illustrated, a fluid coupling ll. of the Eottinger type, planetary. gearing l3 and clutch mechanism M;

The fluid coupling comprises an impeller [5, a primary rotor 16 and a secondaryrotor H. The

impeller and a flanged sleeve l8 are fixed to the-- crankshaft by bolts [9 forming power input means. shaft 20 projects through the sleeve-section and hasa sleeve 2| splined thereto, the sleeve and the sleeve section being connectible in drive relation by an overrunning clutch 22 of the coil spring type. The primary-rotor lt'has a hub 23 fixed thereto and splined' to sleeve shaft 24- telescoping a portion of shaft 2% portion of shaft 24.

The fluid coupling l2, gearing l3 andclutch mechanism M are housed in a casing comprised of sections 26, 27 and 23 suitably secured together. Section 25 houses'thegfluid coupling and has a rear transverse wall 29, section 21 houses the gearing l3 and has a transversely extending wall as and section 23 houses the clutchmechanism and. has. a transversely extending wall 3| fixed therein. The nested shafts 20, 24 and 25 extend. through and are supported by wall 29 while shafts 23 and 24 extend through and are supported by wall 36.

The planetary gearing includes drivegear 32 fixed on shaftZil, drive gear33 fixed on shat-i224,

driven gear 34 and stepped planet gears 35, Stand they are each rotatably mounted on a pin'38 fixed on carrier 39. Thecarrier has a forward sleeve portion 4Q, telescoping shaft 24 and extending through wall 30, and a two part housing 4| secured together by bolts 42 and splined at 43 to sleeve to. The forward part of housing 4| telescopes shaft 25 and is rotatable-relative thereto.

The housing il encloses and forms a part of a clutch device 44. In such clutch device, ring 45 is splined to the end of shaft 25 projecting into the housing and this ring and the inner peripheral wall of the housing are slotted to alternately receive clutch plates 45. Pressure ring member 47 isactuated to engage the clutch plates audit is normally positioned by coil springs 48 so that the clutch plates are disengaged. A plurality of pistons 49 are arranged in pockets 5!] in the carrier housing and are adapted to actuate thepressure member to engage the clutch devicewhen subjected to controlled fluid pressure in a system connecting star gear pump 5| with the pockets 5!). This pump is arranged in wall 29- and is driven by shaft 25.

A brake device 52 is arranged for actuation to. prevent rotation of the clutch housing M. The.

is obtained through gears 33 and'35 when shaft- 24 is the-driver. High speed driveis obtained when the clutch device 44- is engaged. It is neeessary, in low and intermediate speed'drivea for the brake device 52 to beapplied to prevent The secondary. rotor I! is, fixed to sleeve shaft 25 telescoping a.

The planet. gears. may comprise one or more units each fixed together or formed integrally and 3 retrograde movement of the planetary gearing carrier 39, but the brake device is disengaged when the clutch device is engaged for high speed drive. Likewise, the clutch device must be disengaged when the brake device is engaged.

The specific form of fluid coupling forms the subject matter of my copending application Serial Number 588,617, filed April 16, 1945, which has issued as Patent No. 2,577,404 granted December '4, 1951. The inner surface of the impeller is dished and carries radial vanes 60 forming curved passages that are open to passagesin the primary rotor formed by radial vanes 6|. The secondary rotor is dished and has radial vanes 62 forming passages. The primary rotor has a dished shield ring 63 open toe. dished shieldring 94 of the impeller. The shield rings serve to divide the passages of the impeller and the primary rotor to form inner and outer circulation circuits for the fluid. The impeller I5 circulates the fluid in the coupling which will flow in one circuit interiorly of the shield rings and in another circuit exteriorly of the shield rings, such circuits being indicated by arrows. In the outer circuit fluid from the impeller discharges into the primary rotor, from the primary rctor it passes to the secondary rotor, then to the second stage of the primary rotor, and then back to the impeller. These circuits have their axes normal to the axes of the impeller and rotors which arrangement is known as the Fottinger type of coupling. The rotors can rotate relative to the impeller and to each other.

Gear 34 of the planetary gearing is splined to driven shaft 79 and a tail shaft H is connected in drive relation therewith by a torque-speed device. The tail shaft is connectible with a propeller shaft 12 by the clutch mechanism l4. Shaft 'H .has arms 13 extending radially from its forward end and extending through bearing members l4 rotatably mounted on flyweights 1'5. The flyweights are pivotally mounted on pins 16 fixed to flange Ti on :the rear end of shaft HI. The weights are urged inwardly by torque and outwardly by centrifugal force and they are utilized to controlclutch device 44 as well as being a part of the drivezconnection between shafts l and The reverse drive gearing is contained. in casing section'2l and encircles the driven shaft 19. Drum 18 is rotatably mounted on an extension 19 of theplanetary gearing carrier 39, and the drum hasan internal gear 83 arranged to mesh with an idler gear 8| mounted on pin 82 fixed to the shaft flange TI. The idler gear also meshes with gear 89 on the carrier extension 19. A sectional brake band 84 surrounds drum 18 and is actuated to engage the drum bya rubber tube 85 carried by casing 36 fixed to casing section 21. band is normally expanded by suitable spring means between the sections and is contracted by the rubber ftube when it is inflated by pressure fluid in a system supplied by pump The clutch mechanism 14 includes a disk member 81 fixed on the front end of shaft 12 having clutch teeth 88 and a peripheral cone brake surface 89. Clutch member 90 is slidably splined on shaft H and has teeth 9| engageable with teeth 88., This clutch member 99 may be shifted by any well known mechanism engaged with its radial extension 92. A synchronizer disk 93 has a brake rim 94 adapted to engage the surface 99 tobring shafts 1| and 12 to the same speed beforethe associated clutch teeth can be engaged. Disks 93 and 95 are connected by pin 99 extending through an'opening 91 in extensionv 92. An

The brake angular spring 98 also extends through the opera ing and is bent to embrace disks 93 and 95. As the clutch member is shifted toward shaft 12, spring 98 is engaged and carries the synchronizer disks and 93 therewith engaging brake rim 94 with surface 89. Further continued movement of the clutch to engage teeth 9| with teeth 88 is prevented until shafts 'H and 12 have been brought to the same speed by engagement of the pin cone surface 96 overlying opening 91 due to their relative rotation. When the direction of relative rotation between shafts 'H and 12 beginsto reverse, the pin cone surface 99 is moved rotationally off the edge of opening 91, and opening 91 being larger than the enlarged portion of the pin 99 adjacent pin cone surface 96, said pin will be moved through opening 91, thereby allowing the clutch member 90 to be moved into engaged relation with shaft 12.

First or low speed forward drive is obtained by engaging brake 52 to prevent retrograde movement of carrier 39 when the crankshaft is driv ing shaft 29 through the overrunning clutch connection 22. This will occur automatically when the crankshaft speed is low so that fluid pressure in the coupling is ineffective to drive the rotors at a drive effective speed. Assuming that clutch mechanism [4 is engaged and that clutch device 44 and the reverse brake device are disengaged, the low speed drive will flow directly from the crankshaft through clutch 22, shaft 2!), gears 32, 36, 31 and 34 to shaft 19, the torque-speed device, shaft H, clutch mechanism It and shaft Second or intermediate speed drive is automatically obtained with the controls in the same relation as in first speed drive when the impeller rotation creates a fluid force in the coupling sufficient to rotate the primary rotor at a speed where it drives the stepped planet gear unit at a speed causing shaft 29 to overrun the crankshaft. The drive will then flow through shaft 24, the coupling impeller and primary rotor through gears 33, 35, 3'! and 3A. shaft 10, the torque-speed dzevice, shaft H, clutch mechanism I4 and shaft High speed drive takes place at some predetermined operating condition when vehicle speed overcomes torque whereby the flyweights move out to condition the hydraulic system to engage clutch device 44. At the same time provision is made to disengage brake 52. The reverse brake is disengaged in all forward speed drives. The

carrier 39 is now fixed to rotate with the secondary rotor l1 and such rotor is being driven substantially at the same speed as the impeller and primary rotor except for some slip. The crankshaft will rotate shaft 20 directly and the 1 as the impeller, and, as the secondary rotor is connected directly with the carrier, by the clutch device, fluid in the coupling serves as reaction means for the drive. As a result there will be two paths of power flow from the crankshaft to the driven shaft, one path being through the low speed gearing and the other path being through I the coupling secondary rotor, the clutch device The high speed drive will f 44 and the carrier. be less than I:I because of slip caused by reaction through the secondary rotor. In this drive.

the primary rotor depending upon the fluid force present in the coupling. In either case the carrier 34 is free to turn 'rearwardly asbrake device 52 and clutch device 44 are released. Rotation of the planetary unit by either gears 32 or 3.3. will turn the carrier in a reverse direction rtating .gear 80 therewith and carrying disk 11 therewith through the planet gear 8| meshing therewith, but the speed will be reduced because of gear 8| meshing with gear 83 on the stationary reaction member '18. At the same time gear 80 will be carried in a reverse direction by gears 34. and 31, although gear 34 is rotating on its axis tending to drive gear 31 and shaft I0 forwardly. Thus the carrier '39 and shaft I0 contribute to the reverse drive which is reduced through gear 8i. The secondary rotor II will idle because clutch device 44 is disengaged.

The fluid system for the controls in the transmission is shown in Fig. 3. Pump is suitably connected with the transmission sump I00 by conduit I01, and another pump I02 is connected with the sump by conduit I03. Pump I 02 is carriedin wall 3I and is driven by shaft II. There are two pressure fluid circuits, one for the clutch device 44 and another for the brake devices 52 and 85, and a selector device I04 alternately controls flow to brake device 52 and clutch device 44. The. selector .device comprises a housing I05 in which is arranged a valve I06 and spring I01. The fluid control circuit for brake device 52 comprises pump 5|, conduit- I08 connecting the pump 5I with selector housing I05 and the conduit I09 connecting the selector housing with the interior of brake. tube 54. The selector valve has a peripheral recess III for establishing'communication .between conduits I08 and I09 when in one position. The conduit I 08 has a branch I I I leading to the interior of brake tube 85 and'flow to the'sele'ctor .housing or the branch is controlled by'valve IIf2.

The fluid control circuit for clutch device 44 comprises pump I02, conduit 'II3 leading from the. pump to the housing I05 of the selector device and conduit II4 leading from housing I05 to pockets 50. A branch conduit II5 connects conduit II3 with one end of housing I05 so that fluid "pressure may act against valve I06 to'place the recess III) to establish communication between conduits I I3 and H4. Normally, spring I01 acts to move the valve to shut off conduit I I4 from conduit I I3 so that the clutch device 44 will disengage and to open communication between conduits I08 and I09 to'engage brake device 52. Thus pressure in the clutch fluid actuating circuit controls alternate engagement and disengagement of brake device 52 andclutch device 44. Pressure in the fluid circuit for the clutch device 44 is preferably controlled by the torquespeed device, previously referred to. Conduit I I3 terminates in an axial passage H6 and a radial ventpassage II! in shaftj'I'I. A seat ring '8 is fixed in the vent passage and fluid venting therethrough is controlled by a ball valve II9 seated under pressure of spring I20. One of the flyweights 15 carries a stem I 2| extending through-the seat ring for controlling the positionof the bal valve relative to its seat. The arrangement is such that thevalve will be un- 6. seated while the fiyweight is in an inner range of its centrifugal movement, and seated while the fiyweight is in an outer range of its. centrifugal movement. The selection of the length of stem I2.I determines the point in the fiyweight movement at which valve opening and closing :is effected. Thus the venting of conduit I13 may, be,

prevented to supplypressure fluid to the selector device so that the valve will shift to allow J'fluid flow to engage clutch device 44, and ventingof conduit II3 will relieve pressure in conduit H3 so that spring I01 will seat the valve to break the fluid circuit to the clutch device andestab-v lish the fluid circuit to the brake devices 52 -or 85, depending on the position of valve II 2. When reverse drive is established, torque will move. the flyweights outwardly which would allow valve I I9 to seat and thereby cause engagement of the clutch device 44, but such clutch engagement/is prevented by valve I25 in conduit I I3. This valve I25 may be operated by any conventional means.

to vent line I I3 when reverse drive is established, and such valve may be operated by the means provided to control valve '2 so that valve I25 opens when valve H2 is adjusted to allow fluid flow to reverse brake tube 85.

The mechanical connection between the gearing and the crankshaft insures drive without slipfor the low speed drive and the utilizing of'such means, a fluid coupling having an impeller driven.

by the input means and a rotor, a driven shaft having a gear fixed thereto, a primary shaft having a gear fixed thereto, an overrunning clutch between the input'means and the-primary shaft, a shaft fixed to the rotor, torque multiplying gear means meshing with the gears on said driven and primary shafts, a carrier for the gear means, means operable to brake the carrier, and a clutch device operable to secure the rotor shaft and the carrier together for unitary rotation.

2. In a power transmission, a power input shaft, a driven shaft, a fluid coupling including an impeller fixed to the power shaft and two rotors, said impeller and rotors having a plurality of segmentally shaped radially disposed fluid circulating passages formed therein, and the 'rotors being disposed to successively receive the fluid circulated by the impeller, planetary gearing connected with the driven shaft,'a planet gear carrier, means for mechanically connecting-the gearing and the input shaft, connections between one of the rotors and the gearing, and means operable to connect the other rotor for unitary rotation with the carrier.

3. In a power transmission, a power drive shaft, a driven shaft, a fluid coupling including an impeller fixed to the drive shaft and primary and secondary rotors through which fluid is cir-' culated in series from the impeller, planetary gearing connected to the driven shaft, a carrier for thegearing, means for'brakin'g' the carrier,

a mechanical connection between the drive shaft and the gearing including an overrunning clutch, a mechanical connection between the gearing and the primary rotor, and clutch device for connecting the secondaryrotor and the carrier for unitary rotation, said secondary rotor and said drive shaft acting jointly to drive the gearing when the clutch device is engaged.

4. In a power transmission, a power drive shaft, a driven shaft, a fluid coupling including an impeller fixed to the drive shaft and primary and secondary rotors through which fluid is circulated in series from the impeller, planetary gearing including a carrier and a multiple gear planet mounted on the'carrier and geared to the driven shaft, a first speed mechanical drive connection including an overrunning clutch between the drive shaft and one of the gears of the planet, a second speed mechanical drive connection between the primary rotor and another of the gears of the planet, a third speed mechanical drive connection including a clutch device between the secondary rotor and the carrier, and a brake operable to prevent retrograde rotation of the carrier when the clutch device is released.

5. Transmission mechanism comprising a drive shaft, a driven shaft, a fluid coupling having an impeller fixed to the drive shaft and two rotors, planetary gearing having a carrier and two gear trains connected to drive the driven shaft, means including an overrunning clutch for connecting the drive shaft with the low speed gear train, means connecting one of the rotors with the high speed gear train, a connection including a clutch I the lower speed shaft to rotate with the impeller,

the higher speed shaft being fixed to rotate with one of the rotors, means operable to connect the carrier and the other rotor to rotate together, and means operable to prevent retrograde rotation of the carrier when the means for connecting the carrier and rotor is ineffective.

7. In a transmission mechanism, a fluid coupling having a power operated impeller and a rotor, a driven shaft, an output shaft, an over running clutch for connecting the impeller and the output shaft to rotate in unison, planetary gearing including a carrier connecting the output shaft with the driven shaft, a shaft fixed to the rotor, a carrier extension into which the rotor driven shaft extends, brake means engageable with the carrier extension, and a positive clutch device between the carrier extension and the adjacent rotor shaft for effecting unitary rotation of the rotor and the carrier.

8. In a transmission mechanism, a fluid coupling having a power operated impeller and primary and secondary rotors, an output shaft, an overrunning clutch for connecting the impeller and said shaft to rotate in-unison, a second rier extension surrounding the output shafts forming a housing, a brake for engaging the carrier extension, a shaft fixed to the secondary rotor extending into the housing, clutch means in the housing for connecting the carrier extension to the secondary rotor drive shaft, pressure operated means in the housing for engaging the clutch means, and spring means in the housing for normally moving the clutch engage means to disengaging position.

9. In a transmission mechanism having change speed gearing, a fluid-operating device for effecting a reduced drive through the gearing, a shaft driven by the gearing, a tail shaft, a pivoted lever rotatable with one of the shafts, a pivoted connection between the lever and the other of said shafts and adapted to transmit torque between the shafts, weights on the pivoted lever positioned to cause the centrifugal force developed in the weights to oppose the resistance to rotation imposed by the load on the tail shaft, a fluid system for controlling the fluid-operated device, a valve in the fluid system, a second fluid system connected to the valve, a spring for moving the valve to operate the fluid-operated device, said second fluid system acting upon the valve to oppose the spring. a vent valve for the second system, and a connection between the vent valve and the centrifugal weights whereby to move the vent valve to vent the second system when the weights are moved radially inward and thereby to effect a reduced drive through the gearing.

10. In a transmission mechanism having change speed planetary gearing, a carrier for the gearing, a shaft driven by the gearing, a tail shaft, and a brake device operable to hold the carrier against rotation to effect a reduced speed drive through the gearing, control means for the brake device comprising pivoted flyweights rotatable with the driven shaft, means connecting the tail shaft to the flyweights to transmit the drive from the driven shaft to the tail shaft through the flyweights, said means actin upon the flyweights in opposition to centrifugal force developed in the flyweights, a pressure fluid system including a fluid pressure controlled valve for applying the brake device and operable to move the fluid pressure controlled valve to its brake releasing position when pressure is released in the system, a second pressure fluid system controlling said valve, a vent valve in the second fluid system, and means movable with the flyweights to move the vent valve to its venting position when the torque transmitted through the flyweights exceeds a predetermined value, thereby applying the brake to effect a. reduced speed drive through the gearing.

ROBERT P. CLIFTON.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,308,547 Schneider Jan. 19, 1943 2,316,390 Biermann Apr. 13, 1943 2,324,713 McFarland July 20, 1943 2,326,994: Dufiield Aug. 17, 1943 2,332,593 Nutt Oct. 26, 1943 2,355,427 Duflield Aug. 8, 1944: 2,373,234 Duflield Apr. 10, 1945 2,378,577 Oldfield June 19, 1945 

